Indeed, while his career has taken him to Real Madrid, Bayern Munich and PSG, Clement says Kakuta remains the best young prospect he's worked with.
He recalled to Tribalfootball.com: "I'm not sure about (whether he could've done) more, but I thought at the time when we took him, Gael Kakuta a French player who joined us when he was 16, he came form Lens in France and he worked with me initially in the youth team... he is the best young player I've ever seen."
Clement continued, "Left footed, quick, could play as a number 10 or he could play as a winger coming inside, incredible talent. He played in the first team, not very many games but I think he found that initial step quite hard of going from youth football to senior football and in the end it wasn't to be for him at that level."
Kakuta, now 32, is playing for Ligue 2 Amiens back home in France alongside former England striker Andy Carroll. Clement insists there's no exact formula of guaranteeing a young player's success in the senior game.
Clement was with Chelsea when Declan Rice was released as a junior. The now Arsenal midfielder captained England in Tuesday night's 2-2 draw with with Belgium.
He continued: "He (Kakuta) has ended up having a good career, he plays for Amiens now in France. I think he would be the one. But it just shows that there's no one way of doing it, you don't always know, it's not always crystal clear.
"You see loads of examples of young players who are released by certain clubs and in the end they become 100m players. I mean Chelsea let Declan Rice go, so these things happen. And then on the other hand, you get these super talents when they are young you think 'wow, what a great chance that he has to go all the way to the very top' and it just doesn't quite work out and it's not always easy to put your finger on why that is, there's lots of variables involved.
"But I think he (Kakuta) was a fantastic young player who I worked with who maybe didn't get to the level that a lot of people thought he would."